1. Field of the Invention
The present invention relates to a printing system having an image supply device and a printing device, which carries out printing of an image by means of the printing device on the basis of image data supplied from the image supply device, and the image supply device, and a control method for controlling the device.
2. Description of the Related Art
In recent years, a so-called digital camera direct print system, in which a printer and a digital still camera (hereinafter referred to as a DSC) are directly connected to each other via an interface such as USB, and a photographic image stored in a storage medium (a memory card) of the DSC is transmitted to the printer so as to be printed, has become common and general on the market.
In the print system like this, generally, printing is carried out by transmitting a JPEG file intended for printing from the DSC to the printer and by performing decompression, color conversion, resizing, and the like on the printer side to convert the file into a printable data format.
On the other hand, in Japanese Laid-Open Patent Publication No. 8-32911, Japanese Laid-Open Patent Publication No. 10-290470, and Japanese Laid-Open Patent Publication No. 2003-134457, a system is proposed in which the printing is carried out after processing a photographed image especially for printing on the side of the DSC and then the photographed image is transmitted to the printer.
In Japanese Laid-Open Patent Publication No. 8-32911, a digital camera direct print system is proposed in which printing of the image can be carried out in accordance with the image from the DSC and a printing mode on the printer side such as a paper sheet size, using its own print protocol that is not generally utilized.
In Japanese Laid-Open Patent Publication No. 10-290470, the invention is directed to alleviating a processing load on the printer, and the alleviation of the processing load on the printer is implemented by performing the decompression, color conversion, resizing, and the like to the JPEG file on the side of the DSC, to carrying out the conversion processing to convert the image data into a printable data format, and transmitting the converted image data to the printer as printable data.
Further, in Japanese Laid-Open Patent Publication No. 2003-134457, unevenness of color reproduction characteristics regarding each printer is corrected on the DSC side, and the corrected image data is converted into the common image file format such as JPEG and transmitted to the printer. It is described therein that it becomes possible to obtain a stable image not dependant on printing characteristics regarding each printer.
By means of a standard called “PictBridge”, which defines a communication procedure in the digital camera direct print system mentioned above, the digital camera direct print system has become more and more wide-spread. Further, a technology for obtaining high image quality in the DSC has also drastically progressed. The resolution of image data photographed and stored by the DSC had been one million to two million pixels per image at the maximum until a few years ago. However, in the recent years, the DSC which is capable of photographing and storing an image with a high resolving power of eight million or more pixels per one image has come to the market.
In accordance with the increase in the resolution in the DSC, in a digital camera direct print system, new problems as described below have arisen. (1) The pixel number to be processed on the printer side becomes larger and accordingly, the load on the printer is increased. (2) An image file size becomes larger as the pixel number increases, and accordingly, a transfer load of the image file between the DSC and the printer becomes larger.
With these being the causes, a problem has arisen such that a print speed decreases during the printing.
When a part of image processings of the image data for printing is carried out on the side of the DSC in order to share the load of the processing as described in the above known examples, a new problem arises. In each of the known examples, although there is a description about a print mode and the printing characteristics that the printer has obtained from the printer, there is no specific description as to a method for sending and receiving information on the print characteristics of the printer. For example, in a method for transmitting printing performance information of the printer to the DSC, a user can arbitrarily set and select a form of printing such as a size, or a layout within the range that a capability of the printer permits. In the print system like this, when a print condition of the printer is set on the DSC side, the setting cannot always be appropriately performed only by means of using the information from the printer. Especially, in Japanese Laid-Open Patent Publication No. 8-32911, the printer notifies currently printable print mode to the DSC and the DSC alters the print mode in accordance with the notification. For example, when a paper sheet of A4 size is set in the printer body and the printer is equipped with a sheet size detection function, the printer automatically notifies the DSC that the paper sheet size is A4. On the other hand, when the printer is not equipped with the sheet size detection function, the paper sheet size is selected by a setting panel of the printer body and the result of the selection is notified to the DSC. In either of these cases, the current print mode that the printer has recognized is notified to the DSC. That is, the setting that the user desires is not reflected as a result.
In Japanese Laid-Open Patent Publication No. 10-290470 and Japanese Laid-Open Patent Publication No. 2003-134457, there is a description that the print characteristics of the printer are obtained from the printer. However, because the image data to be transmitted to the printer is only converted based on the thus obtained print characteristics, it is not possible to carry out the image processing and the printing processing which complies with the user's desire.
In other words, it is indeed possible to utilize the capacity of the printer in the case where the setting of the print condition is performed by utilizing only the functional information of the printer. However, considering the print time and an image quality of the printing result, this is not always appropriate, or sometimes it is rather inconvenient for the user.